1. Field of the Invention
The invention relates to apparatus for the preparation of charge material for metallurgical fusion processes by combining at least two alloy components in a nonreactive atmosphere.
2. Discussion of Related Art
DE-OS No. 36 28 276 corresponding to U.S. application No. 908,332 discloses a process for the preparation of charge material and for charging, in which first an envelope is formed from an alloy that is not reactive at room temperature, and the envelope is then filled with a metal or an alloy which is reactive at room temperature.
An example of an alloy having both reactive and nonreactive metals is an aluminum alloy containing about 3 percent by weight of lithium, and other alloy elements, e.g. such as magnesium. Such alloys are important in aviation because they reduce the weight of the aircraft so that the saving of fuel costs over the total life of the craft is several times greater than the additional cost of such an alloy.
In the fabrication of such alloys in the form of sheets, extrusions and rough castings, a considerable amount of waste is produced, and when defective parts are returned they constitute scrap. Both the wastes and the scrap are subjected to a recycling process in which the melting process is of decisive importance, and in which the reactive metals--lithium in the case of the example--tend to evaporate, and also the material that is to be worked up does not in every case have the prescribed content of reactive alloy components. In this case, therefore, a higher proportion of the reactive metal must be added to the basic material--aluminum in the case of the example.
The known method, however, is not suitable for the use of contaminated metals and alloys that are reactive at room temperature. The term, "contamination," in this case refers to substances dissolved in the alloy or adhering to the pieces to be worked up, such as cutting oil, drawing oil, iron (detritus from sawblades), fragments of cutting tools, alien metal which is undesired in the alloy that is to be the final product, etc. Such contaminated metals or alloys would first have to be purified, for example by a process of distillation.
The invention is addressed to the problem of combining the process for the preparation of charge material with a purifying process for raw material delivered in contaminated condition.